The Tetracyanopyridinide Dimer Dianion, σ-[TCNPy]2 (2.).
Jingjun HaoArnold L RheingoldMarzieh KavandKipp J van SchootenChristoph BoehmeMarçal Capdevila-CortadaJuan J NovoaEva WössGünther KnörJoel S MillerPublished in: Chemistry (Weinheim an der Bergstrasse, Germany) (2016)
The reaction of 2,3,5,6-tetracyanopyridine (TCNPy) and Cr(C6 H6 )2 forms diamagnetic σ-[TCNPy]2 (2-) possessing a 1.572(3) Å intrafragment sp(3) -sp(3) bond. This is in contrast to the structurally related 1,2,4,5-tetracyanobenzene and 1,2,4,5-tetracyanopyrazine that form π-dimer dianions possessing long, multicenter bonds.